Dishwasher appliances or dishwashers generally include a tub that defines a wash chamber. Rack assemblies can be mounted within the wash chamber of the tub for receipt of articles for washing. Spray assemblies within the wash chamber can apply or direct wash fluid towards articles disposed within the rack assemblies in order to clean such articles. Multiple spray assemblies can be provided including e.g., a lower spray arm assembly mounted to the tub at a bottom of the wash chamber, a mid-level spray arm assembly mounted to one of the rack assemblies, and/or an upper spray assembly mounted to the tub at a top of the wash chamber. Other configurations may be used as well.
Conventional dishwashers have a water supply valve, such as a solenoid valve for filling the tub with water. An average or typical flow rate through a model water supply valve may be premeasured to provide a reference value for multiple assembled dishwashers. When those dishwashers operate to fill their respective tubs, water filling is controlled by time and the premeasured reference value of flow rate. Nonetheless, variations in individual water supply valves may occur, e.g., due to manufacturing tolerances and/or wear. The premeasured reference value may not exactly match the flow rate through the water supply valve of each assembled dishwasher. In order to accommodate variations in assembled water supply valves, dishwashers may be configured to open the water supply valve for longer than would otherwise be necessary. This may lead to an excessive amount of water (e.g., 0.1 gallon) being added for each filling or wash cycle. Moreover, it may lead to higher water consumption and operating costs for the dishwasher.
Conventional dishwashers may also have one or more drain pumps to remove water from the tub. Before assembly, one or more average or typical flow rates through a model drain pump may be premeasured to provide reference values for multiple assembled dishwashers. In turn, draining may be done by time based on the premeasured reference values of flow rates. However, variations in individual drain pumps may also occur, e.g., due to manufacturing tolerances and/or wear. In order to accommodate variations, dishwasher may be configured to operate a drain pump for longer than would otherwise be necessary. This may lead to an excessive drain pump operation, generating undesirable noise and costs. Moreover, it may complicate the dishwasher's ability to drain only a specific amount of water that might otherwise be used in later wash cycles or steps.
Accordingly, it would be advantageous to provide a dishwashing appliance that can accurately and consistently supply and/or drain a select amount of water.